I am going to try and make a long story short.

When I got my car tuned the #3 injector wasn't working (ID 1000's). Tuner said they can get stuck from sitting (They were new but sat on shelf for a year) and he "fixed" the injector.

I got my car tuned and only made 297HP/260TQ with a JDM ITR and a GT3076R @12psi 91 octane.

Tuner said my manifold must suck (Spoolin log).

I took the car to the 1/4 and made an easy shake down pass. Granny shifted at 8K

1.67 60ft
7.93 1/8th @91mph
12.30 1/4 @114.3

The track was so crowded I decided it wasn't worth it to try and make another pass. I had some oil in the catch can from the pass, maybe 1/4 quart.

When I got home I pulled the plugs and they all look great. Since the plugs were out I decided to do a compression test and the #3 cylinder only went up to 70. I brought #3 up to TDC and hooked the compressor to it and the air was coming from the catch can (hooked to back of block) so obviously the piston is toast.

I am thinking we toasted the piston tuning the car and that is why it made such low power per psi.

That would mean that if I replace pistons and am hitting on all 4 cylinders that my tune will be way off right?

Time to rebuild with forged internals and try again.

 

In a perfect world the tuner would use the old tune as a starting point and a retune wouldn't take as long, thus costing you less. However all bets are off depending on the severity when it was tuned. The ignition could be really soft to avoid detonation in that cylinder. Oil in the chamber, AFR way off etc. And this is assuming you rebuild with similar bore, similar compression.

But Im very concerned that the plugs all looked good. Did they look good during the tuning session too?

 

He pulled them once to gap them smaller. Then we made 284hp 248TQ on the gate 10psi. Then raised the boost 1.5 psi with the Hondata boost control solenoid and called it a day at 297hp 260tq.

First thing I am going to do is have the injectors flow tested and see if the #3 injector is still acting funny. Then I am going to CSS the block and put an 11:1 piston/rod combo in there.

Then I am going to read,read,read and learn to tune my own car with my Hondata S300. I am not messing around with pump gas either, I am going with unleaded 109. I tune my Mustang with an Anderson series IV PMS hopefully the Hondata S300 concept is similar.

I am not blaming the tuner 11.3:1 tune on 91 octane was asking a lot.

 

I've taken motors apart where we didn't know a piston broke till it was removed. sometimes a ringland will break just right where it won't physically separate from the piston.. it cracks but never touches the cylinder wall or otherwise interferes with normal operation.

however under high cylinder pressures it will direct gasses past the first ring and cause an oil consumption issue, as you witnessed at the track.

 

Last summer I ran dd and raced with broken ring lands still made 250whp till i bounced the limiter high boost 1st-3rd to end it lol

 

wantboost might have explained why i hadnt commented yet..

 

Yea it's weird when you take the piston out and it doesn't fall apart till it's on the bench lol

although I do have a piston out of an Sr20det where the entire top of the piston separated from the rest of the piston which blew apart and wrapped the rod around the crank. I still have the piston and rod, real good conversation starter lol

 

I cant wait to see what my piston looks like this weekend.

 

sounds like it..




although im shocked that he managed to pull those times with a cylinder out..

 

i figure this goes without saying....but just in case..



dont take it apart to figure out what is wrong if you dont have the money to put it all back together.

 

I already sent the injectors off to get cleaned and tested. The block comes out this weekend and should out shipped out to CSS Monday/Tuesday. 11:1 CP pistons/Eagle rods are on the way. Going for an honest 400whp on a 87octane/109octane 50/50 mix.

 

low boost thats what i made with predominantly 93 octane with 2 gallons worth of 110..

 

I can't wait for my drum of q16 to show up, super happy fun time lol

 

Just like I thought. Finally got around to pulling the piston. Have been real busy with work etc... The other 3 pistons look perfect.

 

no bueno..

 

Same thing happened to me last year with an h22a. It still ran great and even felt the same as when I left the dyno. It smoked out of the exhaust pretty bad so I sold my turbo for parts because it had a small amount of haft play and bought a new one. Put the new turbo on and still smoked the same. WTF? After a month of eliminating pistons because compression testing was coming back really close, I pulled the motor and to my surprise 3 of the pistons had broken ringlands. I could not believe that there was not one single scratch in the cylinder walls.

 

Yeah its crazy. My car wasn't even smoking. I ended up getting CP 9.8:1 pistons and Manley H-beams. The machine shop I use is really behind so it could be a while before its back together. I plan on using the downtime to learn as much as I can about Hondata S300. My old T1 tune should serve as a decent starting point.

 

It's kinda hard to tell but is that an OEM piston?

it's super rare for one to break so low, especially between the 2nd ring and oil control ring. also is that a crack in the ringland between the 1st and 2nd ring or is that just a scratch?

normally an OEM piston always let's go above the 1st ring.

 

In my experience it is ALWAYS the ring land between 2nd ring and oil control... It is thinner there and ring flutter is a bitch.

 

Weird, every broken Honda motor I've personally torn down always has the first ringland broken.

 

Thats gnarly man!

 

I had cracks in both lol

 

Yes OEM piston. Yes that's a crack. Its a shame cause the entire engine looks new except that piston.

 

Uh oh, I think we need to call MythBusters haha.

 

I am smart enough to solve this one. 11.3:1, stock pistons, tubular log w/ITR cams, and a 91 octane tune was a bad idea.